Traverse control valve for machine tools



Sept. 2l, 1965 R. E. PRICE 3,207,045

TRAVERSE CONTROL VALVE FOR MACHINE TOOLS Filed Maron 17. 1961 /0/ H5 v LJ l INVENTO'R Aaa/.PH s. was

ATTORNEY United States Patent O 3,207,045 TRAVERSE CONTROL VALVE FOR MACHINE TOOLS Ralph E. Price, Waynesboro, Pa., assignor to Landis Tool Company, Waynesboro, Pa. Filed Mar. 17, 1961, Ser. No. 96,438 7 Claims. (Cl. 91-448) This invention relates to hydraulic systems, particularly traverse control valves for reciprocable members of machine tools.

A traverse control valve must perform several functions, among which are supplying liuid under pressure alternately to opposite sides of a reciprocable motor, connecting opposite sides of said reciprocable motor with pressure when the motor is idle so that both sides are under the same pressure, controlling the supply of iluid to or from said motor so as to prevent an abrupt start of said reciprocable member. Formerly, these functions required a manually operated start and stop valve, a pressure operated by-pass valve and a pressure operated traverse start cushion valve in addition to the reversing valve and the reversing pilot valve.

It is, therefore, an object of the present invention to combine the start and stop valve, the by-pass valve and the traverse start cushion into a single valve member.

Another object is to provide fluid under pressure for shifting said valve to start position.

Another object is to provide in said valve means for first directing iluid under pressure to the reciprocable motor and then to gradually release the exhaust fluid from said motor.

The drawing is a hydraulic diagram of a traverse control valve for a traversing member of a machine tool.

The drawing shows a hydraulic motor consisting of cylinder 10 mounted on bed 11 of a machine tool, and a piston 12 in cylinder 10. Piston 12 is connected through piston rod 13 and bracket 14 to a movable member 15 of a machine tool, in this case, the work carriage of a grinding machine.

At each end of cylinder 10 is a bleeder port 20 and 21 connected through restrictions 22 and 23 respectively to exhaust passage 24.

luid under pressure is directed to opposite ends of cylinder 10 by a reversing valve 30 in housing 37 through passages 31 and 32. Fluid is also supplied simultaneously to opposite ends of cylinder 10 from pump P through line 33 and restriction 34 to passage 31. Fluid is also supplied from pump P to passage 32 by way of line 35 and restriction 36. Fluid under pressure from line 35 is also conducted through passage to reversing pilot valve 50. Valve is operable in opposite positions to distribute iluid under pressure through passages 51 and 52 to the right and left hand ends respectively of reversing valve 30. The right and left hand ends of valve 30 are in the form of portions of reduced diameters 53 and 54 slidable in cylinders 55 and 56 respectively. Cylinders 55 and 56 are, in turn, connected to passages 51 and 52 respectively. Restrictions 57 and 58 maintain pressure in passages 51 and 52 to shift valve 30.

The rate of movement of reversing valve 30 is controlled by dwell control valves and 61 in lines 62 and 63 respectively between the end portions 53 and 54 of valve 30 and fluid reservoir 64. Fluid is returned from reservoir 64 by gravity through passages 70 and 71 to opposite ends of reversing valve 30.

Exhaust fluid from the opposite ends of cylinder 10 returns to reversing valve 30 through passage 31 to port 75 and through passage 32 to port 76. From ports 75 and 76, exhaust uid is distributed by valve 30 through exhaust passages and 81 -to decelerating valve 85.

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Decelerating valve and reversing pilot valve 50 are both actuated by reversing lever which, in turn, is actuated in a suitable well-known manner by means (not shown) on carriage 15. Valve 85 directs fluid alternately from exhaust passages 80 and 81 to a central exhaust passage 86.

Reversing lever 90 is connected to decelerating valve 85 and reversing pilot valve 50 by means of bolt 92 having a nut 93 at one end and a head 94 at the other end. Lever 90 is attached to bolt 92 by means of nut 95. Nut 95 is adjusted to the left to hold valve 85 in positive relation to lever 90. A predetermined amount of lost motion is provided for valve 50 between nut 95 and head portion 94 of bolt 92. Head 94 is contained in a recess 96 in the right hand end of valve 50.

Passage 86 is connected at all times to passage 87 which, in turn, is connected through restriction 88 to exhaust passage 81 and through restriction 89 to exhaust passage 80. The purpose of this connection is to keep the exhaust system lled with hydraulic iluid.

The means for controlling the flow of pressure and exhaut iluid into and out of housing 37 is a valve member 100 having a land portion 101 for controlling the flow of fluid under pressure in passage 40, and a land portion 102 for controlling the flow of exhaust iiuid in passage 86. Each of the lands 101 and 102 has its left end beveled to provide gradual opening of passages 40 and 86 respectively. An intermediate land portion 103 is positioned closer to land portion 101 than to land portion 102 In the space between land portion 101 and land portion 103 is a radial passage 104. In the space between land portion 102 and land portion 103 is a radial passage 105. Passages 104 and 105 are connected by a longitudinal passage 106.

Operation At the extreme left end of valve member 100 is a narrow land or piston portion 10. Spring 15 holds valve 100 in left hand or inoperative position. In this position, passages 31 and 32 leading to the opposite ends of cylinder 10 are connected through passages 104, 105 and 106 so that iluid is free to move between the opposite ends of cylinder 10 for manual traverse.

When it is desired to apply lluid under pressure to one side or the other of cylinder 10, solenoid is energized by means of a push button or other suitable control means (not shown) to shift valve 121 to the left to direct uid under pressure from pump P through line 125 to line 126. Line 126 conducts lluid through throttle valve 127 and line 12S and against piston 110 to shift valve member 100 to the right against spring 15. During the rst portion of the movement of valve member 100 to the right, land portion 103 moves to block off the passage connected to port 76 so that fluid is no longer free to move from one side of cylinder 10 to the other. At the same time, land portion 102 blocks olf the passage connected to port 75.

As valve member 100 continues to move to the right, land portion 101 gradually moves to connect pressure supply passage 40 with passages 104, 105 and 106 so that when land portion 103 opens passage 77, fluid under pressure will be directed to one end or the other of cylinder 10, in this case, through port 75, passage 77 and passage 31 to the right hand end of cylinder 10.

At this time, land portion 102 has not moved far enough to connect passage 86 with exhaust port 130 and therefore, piston 12 is blocked against movement.

Land portion 102 gradually opens exhaust passage 86 shortly after land portion 101 opens passage 40. Because of this sequence, the pressure in the right hand end of cylinder 10 causes a pressure on the blocked exhaust iluid in the left hand end of cylinder 10. The

gradual opening of passage S6 by land portion 102 permits a cushioned start of piston 12 and carriage 15. Exhaust fluid is discharged through port 130, traverse throttle valve 131 and passage 24 to exhaust passage 24. Traverse speed is determined by the setting of throttle valve 131.

Reversing valve 30 is shown in position to direct fluid under pressure through passage 31 to the right hand end of cylinder 10, moving piston 12 and carriage 15 to the left. As carriage 15 approaches the end of the stroke for which it is set, it shifts lever 90 to the left and decelerating valve 85 to the right. Said valve 85 gradually reduces the rate of flow of exhaust fluid from exhaust passage 80 to exhaust passage 86 to cushion the movement of carriage 15 for reversal.

Because lof the lost motion between lever 90 and reversing pilot valve 50, said valve 5@ does not begin to move until after decelerating valve 85 has performed its function. Valve 50 then connects passage 40 with passage 51 to direct tluid under pressure into cylinder 55 acting on end portion 53 to shift reversing valve 30 to the left at a rate determined by the flow of exhaust fluid from the left end of said valve through line 63 and right hand dwell control valve 61 to reservoir 64.

I claim:

1. In a machine tool, a movable carriage, a reciprocable motor for moving said carriage, a supply of fluid under pressure for driving said motor, a reversing valve for directing fluid alternately to opposite sides of said motor, a valve for controlling the flow of fluid to said reversing valve, said -control valve having a portion operable in one position to provide an unrestricted passage between opposite ends of said motor, said portion also having means to prevent the flow of fluid under pressure to said reversing valve, said control valve having another portion for blocking the flow of fluid under pressure to said first mentioned portion, and `a third port-ion for blocking the flow of exhaust fluid from said reversing valve.

2. In a machine tool, a movable carriage, a reciprocable motor for moving said carriage, a supply of fluid under pressure for driving said motor, a reversing valve for directing fluid alternately to opposite sides of said motor, a valve for controlling the llow of fluid to said reversing valve, said control valve having an intermediate land portion, a radial passage at each end of said intermediate portion, an axial passage connecting said radial passages, said passages serving to connect the opposite sides of said motor when said control valve is in one position, and to connect said reversing valve is in one supply of fluid under pressure in sai-d other position.

3. In a machine tool, a movable carriage, a reciprocable motor for moving said carriage, a supply of fluid under pressure for driving said motor, a reversing valve for directing fluid alternately to opposite sides of said motor, a control valve for controlling the flow of fluid to said reversing valve, said control valve having a first portion operable in one position to provide an unrestricted passage between opposite ends of said motor, said first portion also having means to prevent the flow of fluid to said lreversin-g valve, -said control valve Ihaving a second portion for blocking the flow of fluid under pressure to said first portion, said first and second port-ions co-acting in another position of said control valve to connect said supply of fluid under pressure to said reversing valve.

4. In a machine tool, a movable carriage, a reciprocable motor for moving said carriage, a supply of fluid under pressure for ydriving said motor, a reversing valve for directing fluid alternately to opposite sides of said motor, a control valve for controlling the flow of fluid to said reversing valve, said control valve having a first portion operable in one position to provide an unrestricted passage between opposite ends of sai-d motor, said first portion also having means to prevent the flow of fluid to said reversing valve, said control valve having a second portion for blocking the flow of fluid under pressure to said first portion, said first and second portions co-acting in another position of said control valve to connect said supply of fluid under pressure to said reversing valve, and means to direct fluid under pressure to shift said contr-ol valve between said positions.

5. In a machine tool, a movable carriage, a reciprocable motor for moving said carriage, a supply of fluid under pressure for driving said motor, .a reversing valve for directing fluid alternately to opposite sides lof said motor, a valve for controlling the flow of fluid to said reversing valve, said control valve having a portion operable in one position t-o provide an unrestricted passage between opposite ends of said motor, said passage being operable in another position of said contr-ol valve to connect said supply of fluid to said reversing valve.

6. In a machine tool, a movable carriage, a reciprocable motor for moving said carriage, a supply of fluid under pressure for driving said motor, a reversing valve for directing fluid alternately to opposite sides of said motor, a control valve for controlling the llow of fluid to said reversing valve, said control valve having a land portion at each end and an intermediate portion axially spaced from each of said land portions, a radial passage in each of the spices at each end of said intermediate portion, an axial passage in said intermediate portion connecting said radial passages, said intermediate portion being operable in one position of said control valve to connect opposite ends of said motor Vand in another position to connect said reversing valve with said supply of fluid under pressure.

7. In a mach-ine tool, a movable carriage, a reciprocable mot-or for moving said carriage, a supply of fluid under pressure for driving said motor, a reversing valve for directing fluid alternately to opposite sides of said motor, a valve for controlling the flow of fluid to said reversing valve, said control valve having a portion operable in one position to provide an unrestricted passage between opposite ends of said motor, said portion also having means to prevent the flow of fluid under pressure to said reversing valve, said control valve having another portion for blocking the flow of fluid under pressure to said first mentioned portion, and a third portion for blocking the ilow of exhaust fluid from said reversing valve, said third porti-on having means for gradually releasing said exhaust fluid.

References Cited by the Examiner UNITED STATES PATENTS 1,935,119 11/33 Guild 60-52 2,179,179 1l/39 Fischel et al. 121-38 2,192,839 3/40 Orcutt 121-45 2,631,571 3/53 Parker 121-465 2,633,102 3/53 Baldwin etal. 121-40 2,635,586 4/53 Kuhn 121-157 2,642,945 6/53 Potts 121-157 2,655,904 10/53 Strayer et al. 121-465 2,991,761 7/61 Tydeman 121-45 OTHER REFERENCES Hydraulics and Pneumatics Magazine: published by Industrial Publishing Corporation, Cleveland, Ollio, February 1961, page 58.

SAMUEL LEVINE, Primary Examiner.

KARL J. ALBRECHT, Examiner. 

1. IN A MACHINE TOOL, A MOVABLE CARRIAGE, A RECIPROCABLE MOTOR FOR MOVING SAID CARRIAGE, A SUPPLY OF FLUID UNDER PRESSURE FOR DRIVING SAID MOTOR, A REVERSING VALVE FOR DIRECTING FLUID ALTERNATELY TO OPPOSITE SIDES OF SAID MOTOR, A VALVE FOR CONTROLLING THE FLOW OF FLUID TO SAID REVERSING VALVE, SAID CONTROL VALVE HAVING A PORTION OPERABLE IN ONE POSITION TO PROVIDE AN UNRESTRICTED PASSAGE BETWEEN OPPOSITE ENDS OF SAID MOTOR, SAID PORTION ALSO HAVING MEANS TO PREVENT THE FLOW OF FLUID UNDER PRESSURE TO SAID REVERSING VALVE, SAID CONTROL VALVE HAVING ANOTHER PORTION FOR BLOCKING THE FLOW OF FLUID UNDER PRESSURE TO SAID FIRST MENTIONED PORTION, AND A THIRD PORTION FOR BLOCKING THE FLOW OF EXHAUST FLUID FROM SAID REVERSING VALVE. 